Fall 2014

Daily Notes
Additional Reading
Printable Syllabus
Student Photos

Time and Place:    Tuesday / Thursday 9:30 to 10:45 a.m., Room 300 Leifson Physics

Primary Textbook:  A First Course in Atmospheric Radiation: Second Edition, by Grant W. Petty.
This is a very nice introductory book, with good graphics and straightforward approach.

This course will be taught by W. Patrick Arnott. Office / lab hours Wednesdays 1 pm to 3 pm.

Solar and terrestrial radiation spectra
Radiative transfer in the atmosphere (absorption, scattering, extinction)
Basic radiation laws
Equation of the radiation transfer
Representation of the atmospheric radiation in terms of the electromagnetic theory
Polarization of light
Rayleigh Scattering
Mie Scattering
Theory of multiple scattering for a simple 1-D atmosphere
Spectral properties of the longwave radiation in the atmosphere
Passive and active remote sensing methods
Earth radiation budget
Radiative forcing by gases, aerosol and clouds
Role of radiation in global climate modeling
Blue sky, white clouds, rainbows, halos, glories.

Final examination:  Thursday, 11 Dec 2008–7:30 a.m. - 9:30 a.m. Practice with a previous final exam.

Contact: P. Arnott can be reached at

 Grades:  Midterm  Homework  Final
 grads  30%  50%  20%

Policy on late homework: Not accepted unless circumstances warrant it.


Online learning related to radiation transfer, climate, weather, and fog. (COMET program)

Atmospheric and Earth Sciences

Arnott's IR radiative transfer notes.  

An excellent paper on multiple scattering, Craig F. Bohren.
Multiple scattering of light and some of its observable consequences.
American Journal of Physics, 55(6):524--533, June 1987.

See also the outstanding and free textbook on Radiative Transfer. (Part of the more general collection, by Charlie Zender).

Supplemental Texts:

An Introduction to Atmospheric Radiation, by K. N. Liou. This book is especially strong on mathematical methods.

Fundamentals of Atmospheric Radiation by Craig Bohren and Eugene Clothiaux.

Physics of Climate, by José P. Peixoto, and Abraham H. Oort. Especially good for linking climate with radiation.

Atmospheric Science: An Introductory Survey, by Wallace and Hobbs, especially chapters 6 and 7.

Remote Sensing of the Lower Atmosphere: An Introduction, by Graeme L. Stephens.

Radiation and Cloud Processes in the Atmosphere: Theory, Observation, and Modeling, by Kuo-Nan Liou.

Absorption and Scattering of Light by Small Particles, Bohren and Huffman, 1983.

Light Scattering by Small Particles by H. C. van de Hulst.

Radiative Transfer in the Atmosphere and Ocean, Thomas and Stamnes, 2002 .


Live data on the sun at a multitude of wavelengths.

US Atmosphere Calculations.
Why water is blue.
Quick looks, DOE-ARM, at a wide variety of data from some of the most instrumented sites on Earth.
Glossary of meteorology (nice!).
Atmospheric Sounding Data.
Calculated Soundings from the RUC or MAPS
Basic Equations of Meteorology (from this site).
The Jet Stream.
Solar Energy and Technology. Site 1. Site 2. Site 3. Site 4.

Electromagnetic Theory of Light
Electric Permittivity definition, and the Speed of Light.

Refractive Index definition, including conductivity and permittivity.
Snell's Law for refraction at an interface, and the Critical Angle for total internal reflection.
Overview Maxwell's Equations, and a thorough discussion.
Maxwell's equations of electromagnetism (light) in a vacuum, and in a dielectric.
Current density and conductance. Displacement relationship with polarization and electric field.
Boundary conditions in E&M for a dielectric, and a conductor.
Linear, circular, and elliptical polarization states.
Fresnel Coefficients for Specular Reflection of Light from an Interface.
Brewster's Angle for Polarization at an interface.
Electromagnetic scattering from a homogeneous spherical particle (Mie Theory).
Mie Theory in words.
Rayleigh scattering by dipoles, and the color of the sky.

Quantum Theory
Electron orbitals, site 1, site 2.
Covalent bonds and molecular structure.
Types of Spectroscopy.
Selection rules for atomic transitions in atomic spectroscopy.
Another discussion of selection rules.
Atomic Processes from Astronomy 3730 at CU.

Mie Theory Calculator
Java Mie Code Calculator
Philip Laven Optics of Water Drops with links
Philip Laven Debye Series Solution Water Droplet
Paper on Rayleigh and Mie scattering experiment, spheres.
Lecture notes on Mie scattering, Part 1, Part 2, (from this site).
Skim Milk light scattering demo paper
How the eye response affects our appreciation of blue skies
Measuring Mie and Rayleigh Scattering Cross
Multiple rainbows (13 or so) from water drops and other liquids.
Historical theories of the rainbow.
Atmospheric Optical Phenomena.
Warren Wiscombe has some goodies on light scattering and multiple scattering .
WATER and ICE refractive indices, tabulated, real and imaginary parts.

Coherent backscattering, a feature of multiple scattering.
Monte Carlo method of multiple scattering. (simple).
Monte Carlo method, astronomical applications (and site).
Snow albedo measurements and model, including effects of soot.
Snow albedo, Antarctica, including effects of soot.
Simple Model Snow Albedo, Snow Grain Optics, Albedo .
Ideas of direct, diffuse, and total transmitted radiation in the context of 2 stream models in 1-D.
SBDART Radiative Transfer Model.
Craig Bohren's insightful paper on multiple scattering.
Note that expands on Bohren's paper, with applications in society and history.
Melt the ice caps with a fine layer of soot: Demo for the effects of absorption on multiple scattering.
Multiple scattering lidar for cloud measurements, follow on paper as well.

Analytical expression for aerosol radiative forcing.
Jin Xu's thoughts on aerosol radiative forcing, and powerpoint presentation.
Photoacoustic measurements of aerosol light absorption.
Real live aerosol optics measurements at NOAA CMDL sites.
Aerosols and Climate
Smoke Optics Single Scattering Properties
Our aerosol optics measurements during the 2003 IOP at the DOE-ARM CART site.
Sulfate and nitrate aerosol optics and thermodynamics.
Laser heated particles.

Oxygen a band remote sensing of cloud properties.
Sun photometeric measurements of atmospheric water vapor using 940 nm radiation.
Moon's temperature with simple apparatus.
Nasa's Earth Radiation Budget Experiment (ERBE).
Sea surface temperature, chlorophyl, etc for the East.
Sea surface temperature, global.
El Niño, Southern Oscillation Discussion and forecast.
The MFRSR for optical depth and radiation measurements, and how it is used.
Lidar site at the University of Wisconsin. Check out the theses, for example this one.

Daily plots of solar and thermal radiation from the surface, and overview.
Solar radiation basics, and network measurements from the Univ. of Oregon.

Water cloud radiative transfer notes.

Massive collection of cirrus replica.
Hurricane Nora and her consequences (not death and devastation, but beautiful optical displays). Read the publication.

Blackbody radiation overview, and a nice discussion of IR emission from the body.
WATER VAPOR CONTINUUM: A paper that looks at it from a theoretical perspective.
How you measure longwave irradiance, and a comparison of methods.
Arnott's blurb on gaseous IR transfer.
The water tragedy.
Infrared Optical Depth for a water cloud, and retrieved droplet size spectrum.
Calculate MODTRAN3 Atmospheric IR Radiation.
Nice discussion of methane's rising importance in IR transfer.
Global Climate, and Methane's rising concentration (from this site). See also the rise of carbon dioxide.
More on Methane
IR Spectra looking up in the tropics with large water vapor column amount.
Theory of FTIR retrievals.
Application to Tornadic diagnosis.
Current State of the Art.
Some of the class participants enjoying a fine day, and taking measurements.
Downwelling Radiance Measurement, clear, dry sky, and blackbody.
Measured Brightness Temperatures for two very different years, and their soundings. (Skew T's for 15Apr99 and 21Feb01).
Theoretical Molecular Absorption Spectra for Water Vapor, Carbon Dioxide, Ozone, and Methane.
Class of 2004 measurements, 24 Mar 2004.

UV A, B definitions. (image from this site. Curve labeled D is spectrum including only Ozone absorption; B and C include aerosol.)
Absorption spectra of gases in the UV, at specified concentrations.
Dobson Units Definition . (image from this site. Another image from another site that also explains the ozone hole.)
Real Live UV-B and Column Ozone Measurements, including those at DRI's Storm Peak Laboratory.
Actinic Flux theory for broken cloud fields.
Check out the extinction coefficient of Nitrogen Dioxide gas as a function of wavelength.
Rayleigh scattering coefficient for the atmosphere, and how it is determined, from the UV to the near IR.

Climate and Radiation
Tropopause height as a tool to study short term climate change (especially that from you and I).
Does hurricane intensity depend on greenhouse gas concentration?
TRMM satellite view of the most intense thunderstorms on Earth.
Agriculture saves us from the ice age, fossil fuel use fries us: The Ruddiman Hypothesis.
Arrhenius and global warming; the early years and a paper.

Dan Bruton, Stephen F. Austin University, Radiation transfer site.
Climate and Radiation at NASA Goddard. Warren Wiscombe has some goodies.
Irina Sokolik, Georgia Tech, Atmospheric Radiation Transfer.

ATMS Programs (search for others also)
University of Nevada Reno Graduate and Undergraduate programs.
University of Illinois.
University of Washington.
University of Wisconsin.
University of Arizona Dept Atmos Sci.
University of Utah.
North Carolina State University, Department of Marine, Earth, and Atmospheric Sciences.
Penn State University.
New Mexico Tech Graduate Program in Atmospheric Sciences.
UCLA Department of Atmospheric and Oceanic Sciences.
University of Colorado Department of Atmospheric and Oceanic Sciences.
Colorado State University Department of Atmospheric Sciences.
SCRIPPS Center for Atmospheric Sciences.
University of Maryland Department of Atmospheric and Ocean Sciences.
University of California Davis Atmsospheric Sciences Program.
University of Wyoming Atmospheric Sciences Program.
University of North Dakota Atmospheric Sciences Program.
University of Nebraska Atmospheric Sciences Program.
University of Indiana Atmospheric Sciences Program.
University of Alaska Atmospheric Sciences Program.

Other helpful references: Radiation transfer sites.

DRI has a well-equipped Atmospheric Science library.